Load Analysis in the VM Container 

Use

In addition to monitoring (see Monitoring the VM Container) load analysis is also a means for the administrator to find out whether the system is correctly configured for the designated application system. Any overload situations that occur could often be avoided.

The following section describes how the load can be analyzed when the VM is in operation.

Features/Activities

Snapshot Analysis

With the Work Process Overview (transaction SM50) you can ascertain which applications are currently running on an application server and how long they have been running for. For instance, if all the work processes of type Dialog are busy, or some applications have been running a very long time for dialog work processes, the system may well be overloaded at the moment.  You can tell whether an application is executing a Java application component in the VM Container from what is shown in the Report column. If it is a Java application component, the column contains the name of the Java function module starting with the word, “function”, (for example, Function SPC_GET_PRICING_PROCEDURE), rather than the name of an ABAP program. Developers can find more information about this Java function module in the Function Builder (transaction SE37).

If you ascertain that the application is executing Java function modules in the VM Container, you can analyze the execution status more closely in the VM Overview (transaction SM52).

Statistic Record Analysis

For each dialog step a statistic record possibly with subrecords is created. In particular, if the VM Container is used, subrecords are also created with information about the VMC usage.

To analyze whether overload situations recently existed (for instance on the same day), you can use the SAP workload single record analysis (transaction STAD) to examine execution times and resource consumption.  In the list you can identify statistic records that use the VM container from the times shown in column VMC elapsed time. The relevant times are greater than 0 ms.  By double-clicking on a line and choosing the pushbutton VMC, details about execution in the VM container are displayed.

For more information see Statistics in the VM Container.

Display Load in the Past Days, Weeks, and Months

In both the System Load Monitor (transaction ST03) and in the Global System Load Monitor (transaction ST03G) you can find diverse information about time and resource consumption in the following analysis aggregates:

·        System load overview (resource consumption per task type (dialog, update, etc.)

·        Top response time

·        Transaction profile (resources consumed by the applications used)

·        Time profile (resource consumption depending on time of day)

·        VMC profile (detailed breakdown of the resource consumption depending on the time of day)

In particular, the memory and CPU consumption in the VM Container are indicated in these monitors, as well as details of the garbage collection in the heap of the used Java VMs, and the garbage collection in the shared memory (shared garbage collection, shared GC).